Radiation sensing system

Abstract

Disclosed is a radiation sensing system including signal accumulating type radiation sensor device having at least one radiation sensing element responsive to a radiation to produce an electrical signal, a presetting circuit for presetting the time for the accumulation of the signal by the sensor device, a first control circuit for dividing the signal accumulating time preset by the presetting circuit into a plurality of time sections discontinuous, namely, having separating periods interposed therebetween, and causing the sensor device to effect the accumulation of the produced signal of the sensing element only during each time section, and a second control circuit for reading out the accumulated signal from the sensor device after termination of the signal accumulation by the plurality of time sections.

What we claim is: 
     
       1. A radiation sensing system including: (A) signal accumulating type radiation sensor means having at least one radiation sensing element responsive to a radiation to produce an electrical signal;   (B) presetting means for presetting the signal accumulating time of said sensor means;   (C) first control means for dividing the signal accumulating time preset by said presetting means into a plurality of discontinuous time sections and causing said sensor means to accumulate the produced signal of said sensing element only during each of said time sections; and   (D) second control means for reading out the accumulated signal from said sensor means after termination of the signal accumulation by said plurality of time sections.   
     
     
       2. The system according to claim 1, wherein said first control means is designed to vary the number of sections of the accumulating time in accordance with the length of the signal accumulating time preset by said presetting means. 
     
     
       3. The system according to claim 2, wherein said first control means is designed to divide said preset accumulating time so that the time lengths of said time sections are equal to each other. 
     
     
       4. The system according to claim 3, wherein said first control means is designed to divide said preset accumulating time into a plurality of discontinuous time sections which are within a predetermined period. 
     
     
       5. The system according to claim 4, wherein said first control means includes a rate multiplier. 
     
     
       6. The system according to claim 1, 2, 3, 4 or 5, where said presetting means is designed to preset said signal accumulating time on the basis of the level of the signal read out from said sensor means. 
     
     
       7. The system according to claim 1, 2, 3, 4 or 5, further including: third control means for inhibiting the accumulation of the signal in said sensor means during the periods other than said plurality of time sections for the signal accumulation controlled by said first control means.   
     
     
       8. A radiation sensing system including: (A) at least one radiation sensing element responsive to a radiation to produce an electrical signal;   (B) at least one accumulating element for accumulating therein the produced signal of said sensing element;   (C) first control means for dividing a preset signal accumulating time into a plurality of discontinuous time sections and causing said accumulating element to accumulate the produced signal of said sensing element only during each of said time sections; and   (D) second control means for reading out the accumulated signal from said accumulating element after termination of the signal accumulation by said plurality of time sections.   
     
     
       9. The system according to claim 8, wherein said first control means is designed to vary the number of sections of the accumulating time in accordance with the length of the preset signal accumulating time. 
     
     
       10. The system according to claim 9, wherein said first control means is designed to divide said preset accumulating time so that the time lengths of said time sections are equal to each other. 
     
     
       11. The system according to claim 10, wherein said first control means is designed to divide said preset accumulating time into a plurality of discontinuous time sections which are within a predetermined period. 
     
     
       12. The system according to claim 11, wherein said first control means includes a rate multiplier. 
     
     
       13. The system according to claim 8, 9, 10, 11 or 12, further including: a clearing element for clearing the produced signal of said sensing element; and   third control means for causing said clearing element to clear the produced signal of said sensing element during the periods other than said plurality of time sections for the signal accumulation controlled by said first control means.   
     
     
       14. The system according to claim 13, wherein said sensing element, said accumulating element and said clearing element together constitute a radiation sensing device. 
     
     
       15. The system according to claim 14, wherein said sensing device further includes: an output portion for putting out the accumulated signal of said accumulating element; and   a transfer portion for transferring the accumulated signal of said accumulating element to said output portion under the control of said second control means.   
     
     
       16. The system according to claim 15, wherein said sensing device is a CCD sensor. 
     
     
       17. The system according to claim 15, wherein said accumulating element is provided in at least a portion of said transfer portion. 
     
     
       18. The system according to claim 17, wherein said sensing device is a CCD sensor. 
     
     
       19. The system according to claim 8, 9, 10, 11 or 12, wherein said sensing element and said accumulating element together constitute a radiation sensing device. 
     
     
       20. The system according to claim 19, wherein said sensing device further includes: an output portion for putting out the accumulated signal of said accumulating element; and   a transfer portion for transferring the accumulated signal of said accumulating element to said output portion under the control of said second control means.   
     
     
       21. The system according to claim 20, wherein said sensing device is a CCD sensor. 
     
     
       22. The system according to claim 20, wherein said accumulating element is provided in at least a portion of said transfer portion. 
     
     
       23. The system according to claim 22, wherein said sensing device is a CCD sensor. 
     
     
       24. A radiation sensing system including: (A) signal accumulating type radiation sensor means having at least one radiation sensing element responsive to a radiation to produce an electrical signal;   (B) presetting means for presetting the signal accumulating time of said sensor means; and   (C) control means for controlling the accumulation of the produced signal of said sensing element in said sensor means in accordance with the signal accumulating time preset by said presetting means, said control means having a plurality of different control modes, selecting one of said plurality of control modes in accordance with said preset accumulating time and controlling the accumulation of the signal in said sensor means by the selected control mode.   
     
     
       25. The system according to claim 24, wherein the first one of said plurality of control modes of said control means is a mode in which said preset accumulating time is divided into a plurality of discontinuous time sections and said sensor means effects the signal accumulation only during each time section, and the second one of said plurality of control modes is a mode in which said sensor means continuously effects the signal accumulation during said preset accumulating time. 
     
     
       26. The system according to claim 25, wherein said control means includes: an accumulation controlling circuit for controlling the signal accumulation in said sensor means by said first and second control modes in accordance with said preset accumulating time; and   a mode designating circuit for designating the control mode of said accumulation controlling circuit in accordance with the length of the signal accumulating time preset by said presetting means, said designating circuit designating said first control mode when said preset accumulating time is shorter than a predetermined time.   
     
     
       27. A radiation sensing system including: (A) at least one radiation sensing element responsive to a radiation to produce an electrical signal;   (B) at least one accumulating element for accumulating the produced signal of said sensing element; and   (C) control means for controlling the accumulation of the produced signal of said sensing element by said accumulating element in accordance with a preset signal accumulating time, said control means having a plurality of different control modes, selecting one of said plurality of control modes in accordance with said preset accumulating time and controlling the accumulation of the signal in said accumulating element by the selected control mode.   
     
     
       28. The system according to claim 27, wherein the first one of said plurality of control modes of said control means is a mode in which said preset accumulating time is divided into a plurality of discontinuous time sections and said accumulating element effects the signal accumulation only during each time section, and the second one of said plurality of control modes is a mode in which said accumulating element continuously effects the signal accumulation during said preset accumulating time. 
     
     
       29. The system according to claim 28, wherein said control means includes: an accumulation controlling circuit for controlling the signal accumulation in said accumulating element by said first and second control modes in accordance with said preset accumulating time; and   a mode designating circuit for designating the control mode of said accumulation controlling circuit in accordance with the length of the signal accumulating time preset by said presetting means, said designating circuit designating said first control mode when said preset accumulating time is shorter than a predetermined time.   
     
     
       30. The system according to claim 27, 28 or 29, wherein said sensing element and said accumulating element together constitute a radiation sensing device. 
     
     
       31. The system according to claim 30, wherein said sensing device includes: an output portion for putting out the accumulated signal of said accumulating element; and   a transfer portion for transferring the accumulated signal of said accumulating element to said output portion.   
     
     
       32. The system according to claim 31, wherein said sensing device is a CCD sensor. 
     
     
       33. The system according to claim 31, wherein said accumulating element is provided in at least a portion of said transfer portion. 
     
     
       34. The system according to claim 33, wherein said sensing device is a CCD sensor.